My check engine light came on the 1st time on my 1999 Toyota Corolla (has 183,000 miles). The reason was the 02 sensors were burned out. Replaced them ($400 incl. labor). Then, 2 weeks later, check engine light came on. The reason this time: reading was a P0420, catalyst below threshold, bank 1. Mechanic suggested that I change oxygen sensors, perhaps the cables, too. I decided to wait. 2 days later, the check engine light turned off. Is there any rhyme or reason to this? Also, if oxygen sensors were recently changed, is there any other alternative to getting a new catalytic converter just yet?
Check Engine Light P0420 - Catalyst below threshold bank 1 - Toyota corolla 1999?
Need to get a new cat, not much you can do to get around it.
Or just ignore the light.
